Lathe tailstock



oct. 12, 1943. F`.A-.FR1TzsH LATI-IE TAILSTOGK Filed Feb. l1, 1942 2 sheets-sheet 1 l INVENTOR FRANK A. FRITZSGH Oct. 12, 1943. F. A. FRlTzscH l 2,331385 n LATHE TA'ILSTCK Filed Feb; 11, 1942 2 sheets-sheet 2 FRANK A'. FRlrzscH Patented Oct. 12, 1943 LATHE TAIL-STOCK Frank A. Fritzsch, Cincinnati, Ohio, assignor t0 `The Lodge & vShipley Machine Tool Company,

Cincinnati, Ohio, a corporation of Ohio l Application February 11, 1942, Serial No, 430,417

6 Claims.

This invention relates to improvements in the tail stock yof `a lathe.

An object of the invention is to provide in a tail stock structure, improved means to facilitate and expedite use of a lathe for the drilling of holes uniformly to a specied depth,A or, stating it broadly, to repeatedly Aadvance and retract the tail stock spindle measured distances, with a high degree oi vuniformi-ty and` with a substantial saving oi time.

Another object is to provide simple and durable means for the purposev stated, which will relieve the machinist `or voperator of eye strain, unnecessary movements, and fatigue, thereby enabling him to vspeed the fabrication for machine parts and "other products Without 4added effort.

A further "ololiec't of the invention :is the `elimination of arithmetical lcomputations in advanc# ing 4tail stock mounted tools uniformly through or along work pieces successively applied 'to and rotted with the h'ead .stock spindle "of a lathe.

The foregoing and other 'objecftsfare 'attainedby the means described herein and ldisclosed in the accompanying drawings, in which:

Fig. 1 is aside elevational "view-of the'improved lathe 'tailstook, part lheing broken away to illustrate'interior construction.

Fig. '2 'is a lfragmentall fend elevation of the ta'ilstock as -viewed Yfrom left :to night of Fig. l.

Fig. T3 is 'a fragmental cross-'sectional view of la tailstcck embodying aimodiiication.

Fig. 4 'is :a cross-sectional view taken on line 4--4 of Fig. 3.

yAs is Well kn'own to persons :in the machinery art, lathes are sometimes fused for (certain :special operations 'such as thefdrillimgtofholes,foy mountspindle, and rotating afwork piece nre'latye theretoby 'attaching the 'work piece at@ the flye 'spindle throughthe intermediaryfof a chuck, `faceplate, or other suitable holder. :so using the lathe, the "feeding fof the tool tto v.the `yvork .,piece was accomplished'byfifotating the'tailstockfspindle screw manually, fan'dfupon fcompletionof v7the operation, withdrawingktheitotilayreversingthe dimarkings would emerge from the tailstock barrel successively as the spindle handwheel was rotated by the-machinist in feeding the tool to the Work piece. I A

The usual'practice was to insert the drill into the center hole of the tailstock spindle, and clamp the tailstock tothe lathe bed so that the drill point Was'justsufficiently distant `from the work piece to'permitxapplication and removal of the Work piece :to the holding means of the headstock. Then by rotating the tailstock handwheel, the spindle and drill were advanced until the poi-nt of the drill entered vthe work piece up to the full diameter ofthe drill. A-t this point, the machinist noted the reading on the spindle scale at the face of, the tallstock barrel, and then added to the reading the depth of hole t0 be drilled, This procedure irmariably involved calculations in fractions of an inc-h, and mistakes resulting vfrom errors 'in calculations were not uncommon. LObjectionable also under the .common practice related, was the painstaking and time-consuming eiort required'on the part of the machinist, in finding the proper scale line at which Ito stop iieedingthedrillgasthe sca-1e markings -emerged one fby one from ythe spindle barrel. The scale manhingsbeing `line, and sometimes lcovered with lubricant, it was. no easy lmatter for :the machinist to iii-md the proper yline -at which-to stop feeding the drill. Moreover, the .task was .ren- Y dered additionally tedious byreason of theY fact that :the `:sca-le markings had to lbe watched while at the same time the mach-inist actuated the spindle han-dwheel, Yand in :many instances Ano adequate :provision -was made for properly illuminatingwthe `region around and about .the spindle scale. All of this V.detracted from the efficiency-,and .the ablityof the ,machinist to per- Aormghis `duties .withspeedrand accuracy, and resulted .fin sunnecessary mental Aand -bodily fatigue which likewise interfered with eiciency and speedfo'f production.: Moreover, it wasnearly -impossible toscane-.uniformity inthedepthof holes drilled Joy ithe method outlined above, Without the :exercise of r`extraonlinary and painstaking care which :naturally resulted in `fatiguing effort and-aeloss of `valuable time.

All :of l,the foregoing Aobjections are effectively eliminated by means o f the L.present invention, which `simplifies,facilitates and ,expedites the entireprocedure- Y Referrn-grst to the ,illustrations of Figs. l and 2, f,the..character6 ,indicates `the barrel of a lathe tailstock in which isreprocally mounted .the .Spindle .'l.` ,As intordnary practice a screw 8 cooperates with a nut 9 carried by the spindle, in advancing and reti-acting the spindle as the handwheel IS is rotated in one direction or the other. The spindle has the customary tapered center hole or 1oore I2 at its forward end, which normally embraces a dead center, but which in special drilling operations may accommodate also the shank of a drill or other tool I3. Ex-

cept to state that the handwheel I is xed to the rear end of the spindle feed screw, it is deemed unnecessary to further dwell upon the specific means contained within the spindle barrel for supporting the spindle and the feed screw, and for precluding rotation ofthe spindle asit is advanced and retracted bythe action of the' screw. It will be understood, of course, that the base portion I4 of the tailstock is adapted to be fixed upon the lathe bed `at any desired loca tion, in accordance with common practice.

In accordance with the disclosure of Figs. l4

which may be viewed the counting-wheels of` the device. The counter is of standard design and may be purchased on the open market. The counter wheels, as is well-known, willcount and indicate the rotations imparted to the main shaft I9 of the counting device. By rotating the main shaft I9 in one direction the successive complete rotations will beadded up by the counting wheels, whereas by rotating the main shaft in opposite direction, the complete rotations will be subtracted. A resetting lever or finger piece 2B of the counter/serves to restore the counter wheels to zero reading whenever such resetting may be desired.

Upon the rear end of the main shaft I9 of the counter, there is keyed or otherwise fixedly secured a gear 2l. This gear is to be driven from a mainA gear 22 fixed for rotation with the handwheel ID, and in the embodiment illustrated herein, it is expedient to provide an interrne` diate gear 23 for completing the drive and ro'- tating the counterin proper direction to add revolutions as the handwheel is rotated in-clockwise direction, and to subtract revolutions as the handwheel is reversely rotated. As an eX- ample of a proper transmission ratio of gearing to be employed, the feed screw 8 may be of 0.2 pitch, with the circumference of gear 2| being half the circumference of gear 22. In other words, the ratio of driver to driven gear is two to one. and since the counter records each rota-v tion. of its main shaft, the 0.2" pitch of the feed screw will cause the counter to register for each Tlf." linear advancement of the spindle. By properly placing the decimal point at the Window of the counter, the indications upon the counter wheels will `be observable in inches and tenths and hundreds of an inch, as the handwheel is rotated to advance the spindle and the tool held thereby. By altering the ratio of the drive between the feed screw and the main shaft of the counter, the arrangement may be rendered accurately operative for any pitch value of the spindle feed screw, as will be understood.

In order that the mechanism including the counter and the various gears 2 I, 22 and 23 might be protected against abuse or injury, it is con- Cil sidered desirable to provide a gear case 24 upon the end of the tailstocl: barrel, this case being preferably apertured as at 25 to accommodate the hub 26 of gear 22. The lower end of the gear case, at the location 21 may be adapted to contain a suitable lubricant for the gears.

Forwardly of the gear case 24, there may be provided a protective cover 28 for the counter. This cover may be of any acceptable design or configuration, and will preferably be hinged to the tailstock so as to be displaceable and to thereby expose the counter window when necessary. As herein shown, the cover 28 is substantially semi-cylindrical in shape, and includes an interior flange 29 threaded to receive a screw 30 which secures one leaf 3| of a hinge to the cover.

The other leaf 32 of the hinge may be screwed or otherwise fastened as at 33, to the body of the tailstock. The hinge pin is indicated at 34.

If desired, although not of necessity, the cover may be provided with a stop lug 35 for limiting the extent to which the cover may be swung about its hinged mounting. The character 35 indicates a finger piece or handle tobe grasped in swinging the cover to the open position. As previously stated herein, the seat I 5 for the counter preferably is inclined downwardly in the direction of the operators station at the front of the lathe in order to renderfthe counter wheels readily observable to the operator. With counters having windows located elsewhere than at the top thereof, the inclined seat may be dispensed with provided that the window is within the line of sight of the operator normally stationed at the front cf the lathe. From the foregoing, it will be understood that the nature of the counter may determine its angularity and its location upon the tailstock of the lathe.

In the modified structure illustrated by Figs. 3 and 4, 40 indicatesfthe counter, which in this instance is mounted upon the bell end 4I of a barrel 42, which together constitute the frame of the tailstock. The counter includes a reset lever 43 and a main shaft 44 to which is fixedly mounted the gear 45. Through the agency of an idler gear 45, the main shaft 44 of the counter may be driven from the gear41 which is keyed or otherwise iixed to the feed screw 48 so as to rotate with the handwheel 49 which is likewise fixed to the end `of the screw. The frame for the window of the counter is indicated at 50, andthrough it may be observed the numbered wheels of the counter.

In this embodiment of the invention, the bell end of the frame is provided with an end cover 5I housing the variousr gearsr 45, 46 and 41, and as in the Fig. l disclosure, may be apertured at 52 to accommodate the hub 53 of gear 41. One or more screws or other fasteners 54 may be utilized for holding the cover in place. At its upper end, the cover 5I may carry a series of hinge barrels supporting a hinge pin 55 that passes through cooperative hinge barrel means 55 on a protective cover 51 that overlies the window of the counter. The hinge barrel 56 may carry a stop 58 to abut the top ofthe end cover 5I for limiting the swinging movement of the protective cover. With the protective cover hinged to the end cover 5 I, it will be seen to be in such close proximity with the rim of the handwheel as to furnish ready access to thecounter window, the operator being thereby enabled to use one hand in adjusting the handwheel and manipulating the counter cover. The arrangement is common to Figs. l and 3, both of which drawing views dis- .Tof favork. 'fhevcalculating of stool feeds T' in lfractions 'of ,an'inchis entirely eliminated;V there- :by fresulting in fthefliniination of errors 'due 'to' l closeithe proximitycofwithe fcover to -futhe' handrmheclirim.

,ztr Should rbc understood tioatllthe Sfb'eil :end i4 l efe thertailstookcordinarily,dsedetachablef'rom .,theb; Staind-leiloairelgthe usual amounting:` therefor Wherria; eifeotemby means oscrevv threadshi comlllemntarily formed-Within the spindle barrel .andrupon.,thecannular;reduced-enana of: .theme11 iyplacngeshims l2loetweeniithezbelhend atlgofiandtheiterminaliendi @Stefn'the spindle 'rhalreL the bell leend imay be drawn tightly against ith@ :spindle barrel, Y: with ldisposition :of the counter: Windev/tto variousfdegreestoffangu- ,-larity froml a rvertical lplane, uso asilto :fplaceihthe Windowiiin' `the A:j-,direct zlinef :of ssightl, an.: operfatorstationed r atzthel front :of the. 'machine. If necessary orfdcsirablegthezbell endmay heineken .infamy iadiustedpositionof,rctationz with: respect Ato the spindle( barrel, bymeans cof zone-.on more lock-ingegaan. The nckingxboit may ,pass

through an elongated openingior.themen-lend, to; ,provide for the desiredoangnlarity of adjustment. -1

" ,ItNvilL readilyl be rnreciatedvthattthe .use of ts h'rnsft i -may ybe considered .fan alternative .i of i l,the i use ,ot theA4 locking bol.tsz&fi,;afn'd: that theause of, the t locking bolts, mayv Vrender-unilecessary:.the screw. thlfadminnectionw` indicatedzatl'rii. Other such :modifications ,and :changes ein ,structural ,details "will Wat fonce manifest ithemseives :to :the .skilled mechanic. f' Y byactuating'the resetilever:ofxthenounter.' The operator ,then proceeds to `turn ,the 'handwheel and `...advance the tool xinto the Work :piece funtil .the .required .depth of cut appears iinzd'ecimal yvalues upon the Wheelsforthecounter. V:firstprevously stated, .the "counter .will findicate'cthe iteol advancement in .inches .-and Atenths d1undredths of aninchl Upon 4.reachinggthe-zdesirecl depth of cut, the 4,operator will :simply reverse the rotation of the tailstock fnandwheel to :Withdrav/the-tool from'thework piece, and this reversal or retractile movement will result in reverse operation of the counter to subtract rotations of the handwheel. Thus. the counter will add and subtract rotational movements of the handwheel, and will accordingly always indicate the same gure at any given position of the spindle. It Will therefore be evident that repetitive Work will never require a resetting of the counter for successive operations upon identical work pieces, and the drilling operation Will he performed with a high degree of uniformity upon every Work piece operated upon.

The use of the means of this invention is highly superior to the means heretofore employed in operations of the character herein described, as it ensures a high degree of uniformity without Waste of time and expenditure of painstaking effort on the part of the operator. Moreover, the operator is not required to stoop or otherwise discomfort himself in the performance miscalculation Any-operator having the'fmeans .of :this "invention Latil-iis -disposal, may `reasily' ,elortirequiredlto doi-'so Will-be considerably -less ythan :that experiencedvunder the old practice.V

Tit is to? be; distinctlyvunderstood i that fthe? dis- -closureshereinare exemplary only' of various smo'des of applying thfinvention, :since altera- 2tions-an`dy changes in structural-details Will-'depend `largely upon y the `type fof 'tailstock 'to' fbe equipped in accordance with the teaching' herein. Such alterations las may be necessary lto iadapt thef'inventionf-to ther Various fforms of'ftailstocks, Aare accordingly contemplatedtwithin the scopeof ,theinventionaa covered byrthe language of l the ;claims;appende'dfhereto. y i What isclaime'dis: y l Q1. A lathe tailstocl; arranged :"for achieving a high degreeofluniformityeand speed in succesysivelyr operatingiupon Work 'pieces mounted for rotationby.theiheadstock structure of thelathe, Asai-d ltailstock including- Aa A'spindle supporting means, and.. comprisinglin -`combinatien a `nonrotating spindle mounted 'for reciprocation rela- .tiveto sai'dsupporting means-means onthe spin- `dle forli Xedl-y mounting a tool thereon, A*Inc-5ans including 1.a rotatable lfe'ed i shaft for advancing 'andlretracting-the spindlelinearly relative tothe tailstockmnd-'a revolutioncounterincluding drive means `therefor synchronized vivithv vrotational movements/of the spindle feed'shaftior indicating linear @travel of the spindle and the tool mountedthereonfandfa mounting memberfo-r'the counter .adjustable rotationally about the axis oftheffeedshaftftofdispose the counter at various locationsuponan orbit-whose center is the feed shafta'xis.` l l i "12.Alathetailstock,arranged for achieving a high `degree l of i uniformity kand speed in successively operating 'upon Work jpieces mounted l`for rotation-hy Vlthehea'dstockstructure of "the lathe, said tailstock 'including a spindle v"supporting means, andvcomprisingin 'combination a nonrotating spindle mountedffor reciprocationrelative lto -said supportingf'means, means on the spindle for xedly ymounting a tool jthereon, meansZincluding-a rotatable feed shalt for advancing and vretracting Jthe spindle linearly relative Ito the Vf'tailstook, -anda revolution counter including-drive meanstherefor synchronized with rotational movements Yof the spindle feed s haft,

A for indicating lineartravel 1ofthe spindle and the tool mounted thereon, a mounting member for the counter adjustable rotationally about the axis of the feed shaft to dispose the counter at various locations upon an orbit whose center is the feed shaft axis, and a protective counter cover on the counter mounting member and movable likewise along an orbit concentric with orbital movements of the counter.

3. A lathe tailstock arranged for achieving a high degree of uniformity and speed in successively operating upon work pieces mounted for rotation by the headstock structure of the lathe, said tailstock including a spindle supporting means, and comprising in combination a nonrotating spindle mounted for reciprocation relative to said supporting means, means on the spindle for xedly mounting a tool thereon, means including a rotatable feed shaft for advancing and retracting the spindle linearly relative to the tailstock, and a revolution counter including drive means therefor synchronized with rotational movements of the spindle feed shaft, for indicating linear travel of the spindle and the tool mounted thereon, a mounting member for the counter adjustable rotationally about the axis of the feed shaft to dispose the counter at Various locations upon an orbit whose center is the feed shaft axis, and a protective counter cover on the counter mounting member and movable likewise along an orbit concentric with orbital movements of the counter, and means 'pivoting said protective cover for movement through an arc whose plane includes the axis of rotation of the spindle feed shaft.

4. A lathe tailstock arranged for achieving a high degree of uniformity and speed in successively operating upon work pieces mounted for rotation by the headstocl: structure of the lathe, said tailstock including a spindle supporting means, and comprising in combination a nonrotating spindle mounted for reciprocation rela.- tive to said supporting means, means on the spindle for fixedly mounting a toolvtl'iereon, means including a rotatable feed shaft for advancing and retracting the spindle linearly relative to the tailstock, and a direct reading revolution counter including an actuating shaft and a pinion thereon, and drive means therefor synchronized with rotational movements of the spindle feed shaft, for indicating linear travel of the spindle and the tool mounted thereon, and a mounting member for the counter adjustable rotationally about the axis of the feed shaft to dispose the counter at various locations upon an orbit whose center is the feed shaft axis, the driving means for said counter comprising a gear fixed concentrically upon the feed shaft, a second gear rotatably supported upon the rotationally adjustable mounting member in meshing relationship to the first mentioned gear, said second gear being bodily shiftable with said rotationally adjustable mounting member and in constant mesh with the revolution counter pinion to drive the counter irrespective of the positions of rotational adjustment of the mounting member, and means for zeroising the counter reading indicated incident to making the rotational adjustments aforesaid.

5. In a lathe tailstoclr, the combination which comprises: a frame having a longitudinal bore therein, a non-rotatable hollow spindle supported for reciprocation within the bore, a spindle feed screw disposed within the hollow spindle and including means for reciprocating the spindle upon rotation of the screw, said screw having a rear end extending a fixed distance axially from the rear of the frame, a hand wheel fixed on the extending end of the screw for effecting rotation thereof, and a gear mounted axially on the screw intermediate the handwheel and the rear end of the frame, a seat on the frame, a multiple register-wheel direct-reading counter having an indi- .cating device thereon and mounted upon the seat, said seat, frame, and counter being so arranged relative one to the other that the indicia on said counter is readily visible to an operator stationed at one side of said frame, said counter including a driving shaft arranged parallel to the spindle and screw, with the main shaft of the counter extended rearwardly to the plane of the gear aforesaid, means associated with the rearwardly extended end of the counter main shaft effecting a direct driving connection with the gear on the spindle advancing screw, and means for resetting the counter to zero reading independently of extended positions of the spindle relative to the frame.

6. In a lathe tailstock, the combination which comprises: a frame having a longitudinal bore therein, a non-rotatable hollow spindle supported for reciprocation within the bore, a spindle feed screw disposed within the hollow spindle and including means for reciprocating the spindle upon rotation of the screw, said screw having a rear end extending axially from the rear of the frame, a handwheel fixed on the extending end of the screw for effecting rotation thereof, and a gear mounted axially on the screw intermediate the handwheel and the rear end of the frame, a seat on the frame in close proximity with the rim of the handwheel, a hinged cover overlying said seat and so arranged relative to the handwheel as to be manipulated substantially concurrently with actuation of the handwheel by an operators one hand, a multiple register-wheel direct-reading counter having indicia thereon and mounted upon the seat beneath the cover, said seat, frame and counter being so arranged relative one to the other that the indicia on said counter is readily visible to an operator stationed at one side of the frame, said counter including a driving shaft arranged parallel to the spindle and screw, with the main shaft of the counter extended rearwardly to the plane of the gear aforesaid, means associated with the rearwardly extended end of the counter main-shaft effecting a direct driving connection with the gear on the spindle advancing screw, and means for resetting the counter to zero reading independently of extended positions of the spindle relative to the frame.

FRANK A. FRITZSCH. 

